At present, common automatic gas flow controllers have a principal function of stopping a gas passageway by means of a stopper pushed up by pressure difference at both ends of the stopper caused by gas leakage or disorder of a pressure regulator. In practical use, gas coming from an inlet tubeof high pressure or an outlet tube has no gas because of long intermittent use; excessive gas volume may flow into instantly and a gas tank is opened again, forcing the stopper rise up to block the passage as a temporary gas stoppage. On the contrary, when gas inflow is of low pressure, the gas in the tank becomes low, and gas outflow also decreases, causing unbalanced gas supply.